|Agroforestry in the Pacific Islands: Systems for Sustainability (UNU, 1993, 297 pages)|
By definition, trees and tree-like species are essential components of all the agroforestry systems described in the body of this book. These arboreal species now in use need to be preserved and considered first as the basic components of future agroforestry development and in the reversal of agrodeforestation.
Whether on high islands, with their rich soils, varied habitats, and low population densities, on the harsh atolls, almost without soil and short of water, or in home gardens in densely settled urban areas or monocultural rural agricultural areas, all Pacific societies have selected and incorporated into their agroforestry systems a wide range of tree and tree-like species that suited local environmental conditions and met particular cultural needs. Out of the more than 400 such species or groups of closely related species (chapter 10), 100 are listed and described here (table A.2). All were and remain of economic, cultural, and ecological importance in Pacific Island rural and urban agroforestry systems.
The current use of these species, and many others not listed here, in agroforestry is the cumulative result of a selection process occurring over thousands of years. This process began in the ancestral homelands of today's Pacific islanders - in mainland South-East Asia and the archipelagic areas of Indonesia, the Philippines, and Papua New Guinea (known collectively as Malesia). From these areas, valuable cultigens and accumulated knowledge about uses of widespread indigenous species and genera were transferred to the smaller Pacific oceanic islands.
Subsequently, indigenous species encountered in the islands by the settlers were incorporated into Pacific agroforestry systems prior to European contact (Yen 1990). Some of those indigenous species of particular value were, in turn, carried farther east as new islands were settled. Finally, post-Europeancontact introductions have been tested and selected by Pacific islanders themselves and incorporated into indigenous systems to such an extent that the undiscerning visitor or agricultural "expert," and many of the current generation of islanders, believe them to be traditional or even indigenous plants. The integration of species (indigenous and aboriginal and post-European-contact introductions) has been carried out to such an extent that the status of many species remains unclear. Of the 100 tree or tree-like species or distinct cultivars listed here,
74 are usually classified as trees, whereas approximately 26 are better described as shrub-like perennials, which constitute relatively permanent fixtures in Pacific Island agroforestry systems. The classification system is, of course, arbitrary because some species, such as Hibiscus tiliaceus, Pandanus spp., Pipturus argenteus, and Vitex trifolia, are all found as both "shrubs and trees," depending on the environment, the variety, or cultivar. The species classified as shrubs or tree-like perennials (those not normally classified as trees) include:
Table A.1 Origin or antiquity status of the 100 tree or tree-like perennial species listed in table A.2
|Indigenous and aboriginal introductions||37|
|Primarily aboriginal introductions||13|
|Early post-European-contact introductions||24|
In terms of origin, 19 are considered to be indigenous throughout most of their Pacific Island range; 37 are indigenous in parts of their range, usually in the western Pacific, but probably aboriginal introductions into other areas; 13 are probably aboriginal introductions throughout most of their range; 24 are long-established post-European-contact introductions; and 7 are relatively recent introductions (table A.1).
The indigenous species include the coastal or mangrove species Bruguiera gymnorhiza, Calophyllum inophyllum, Guettarda speciosa, Intsia bijuga, Pemphis acidula, Pipturus argenteus, Pisonia grandis, Premna serratifolia, Rhizophora spp., Scaevola sericea, Tournefortia argentea, and Vitex spp., which are either commonly incorporated in, or serve to protect, agroforestry systems from the harmful impacts of the sea and salt spray; coastal or lowland forest species Alphitonia spp., Ficus spp., Pterocarpus indicus, and Rhus taitensis, which are commonly found in active agricultural areas and/or protected when clearing new gardens; and the widespread pioneer species Commersonia bartramia, Glochidion spp., Macaranga spp., and Kleinhovia hospita, which are important, sometimes protected, components of fallow vegetation.
Those that are indigenous to the larger islands of the western Pacific, but possibly aboriginal introductions to some of the smaller islands of the eastern Pacific, include the wild and/or cultivated food plants Adenanthera pavonina, Barringtonia spp., Canarium spp., Dracontomelon vitiense, Ficus spp., Gnetum gnemon, Inocarpus fagifer, Metroxylon spp., Musa troglodytarum, Pandanus spp., Pometia pinnata, Saccharum edule and S. officinarum, and Terminalia catappa. Other culturally important species are Acalypha amentacea, Atu na racemosa, Bischofia javanica, Cananga odorata, Casuarina spp., Cordia subcordata, Cycas spp., Erythrina variegata, Euodia hortensis, Fagraea berteriana, Gardenia taitensis, Garuga floribunda, Heliconia spp., Hibiscus tiliaceus, Morinda citrifolia, Pandanus spp., Polyscias spp., Schizastachyum spp., Securinega flexnosa, Syzygium spp., and Thespesia populnea.
The 13 plants that seem to have been aboriginal introductions throughout their Pacific Island range are mostly domesticated food plants (cultigens). These include breadfruit (Artocarpus altilis and A. marianennsis), shaddock, or pomelo (Citrus grandis), coconut palm (Cocos nucifera), Cordyline terminalis, bush hibiscus spinach (Hibiscus manihot), two banana or plantain cultivars (Musa AAB and Musa ABB triploid), and Malay apple (Spondias dulcis). The remaining aboriginal introductions include candlenut (Aleurites moluccana), betel-nut palm (Areca catechu), paper mulberry (Broussonetia papyrifera), common hibiscus (Hibiscus rosa-sinensis), and kava (Piper methysticum).
The 24 early post-European-contact introductions, all of which have been integrated into agroforestry systems in the Pacific, are mainly food or beverage plants. These include jakfruit (Artocarpus heterophyllus), soursop (Annona muricata), pigeon pea (Cajanus cajan), papaya (Carica papaya), five Citrus species (lime [C. aurantiifolia], sour, or Seville, orange [C. aurantium], lemon [C. Iimonl hystrix?], mandarin orange [C. reticulata], and sweet orange [C. sinensis]), coffee (Coffea spp.), mango (Mangifera indica), horseradish, or drumstick, tree (Moringa oleifera), the Cavendish and lady's finger bananas (Musa AAA and Musa AAB), guava (Psidium guajava), avocado (Persea americana), tamarind (Tamarindus indicus), and cocoa ( Theobroma cacoa). Other important post-European-contact introductions include common bamboo (Bambusa vulgaris), kapok (Ceiba pentandra), flamboyant, or poinciana (Delonix regia), leucaena (Leucaena leucocephala), plumeria, or frangipani (Plumeria rubra), and rain tree, or monkey-pod (Samanea saman).
More recent introductions with increasingly widespread or localized importance in agroforestry systems include Albizia spp., the flowering cassias, or shower trees (Cassia spp.), gliricidia (Gliricidia septum), a range of eucalyptus trees (Eucalyptus spp.), Caribbean pine (Pinus caribaea), big-leaf mahogany (Swietenia macrophylla), and the jambolan (Syzygium cumini).
The common names, scientific names, and synonyms, related species, origin, range and antiquity status, brief physiognomic descriptions, place in Pacific Island agroforestry systems, and information on the cultural and ecological importance of these 100 tree or tree-like perennial species or groups of related species are detailed in table A.2.
Table A.2 One hundred (100) cultivated and wild tree or tree-like perennial species of widespread or considerable local economic, cultural, and ecological importance in Pacific Island rural and urban agroforestry systems (Note: Information provided on: 1) distribution, range, and antiquity status in the Pacific Islands, i.e. whether a given species is indigenous or an aboriginal or recent post-European-contact introduction [Malesia refers to the Malaysian "phytogeographical region," which includes all of the Malay and Indonesian archipelago, the Philippines, and the Island of New Guinea]; 2) the physical characteristics [physiognomy] of the species; 3) its habitat and role within the context of agroforestry systems; and 4) its cultural and ecological utility.)